Production of complex metal compounds of azo dyestuffs



Patented Mar. 15, 1938 UNITED STATES.

PRODUCTION OF COMPLEX METAL COM- POUNDS OF AZO DYESTUFFS Friedrich Moll, Mannheim, and Fritz Lange, Ludwigshafenonthe-Rhine, Germany, 'assignors to General Aniline Works, Inc., New York, N. Y., a corporation of Delaware No Drawing. Application February 4, 1936, Se-

rial No. 62,380. RenewedpSeptember 16, 1937.

In Germany February 15, 1935 13 Claims. (01. 260-122) The present invention relates to the production of complex metal compounds of azo dyestufis'.

Arprocess for the production of azo dyestuffs containing metals is described in our copending application for Letters Patent Ser. No. 27,816, filed June 21st, 1935, according .to which metal compounds of azo dyestufis containing the radicle of .l-hydroxynaphthalenes in which the azo group is present in the 2-position of the naphthalene nucleus are prepared by coupling diazo compounds of aromatic amines, which contain a hydroxyl, carboxylic or alkoxy group in ortho-position to the amino group, with l-hydroxynaphthaleneisulphonic acid or its derivatives, or by coupling the diazo compounds of l-hydroxy-Z-aminonaphthalenel-sulphonic acid or its derivatives with any compounds which contain a hydroxyl group and are capable of'beingco'upled in the position adjacent to the'said group, converting the dyestufis resulting in either of the said methods into their complex metal compounds and then splitting off the sulphonic acid group'from the 4-position of the naphthalene nucleus by treatment with acids or agents supplying acids.

' We have now found that similarly valuable dyestuffs can be obtained by subjecting the metalcontaining and in particular the chromium-containing azo dyestuffs derived from diazo compounds of 2-amino-l-phenoll sulphonic acids substituted in the 5-position and components which are capable of coupling in an ortho-position to a hydroxylgroup to (the treatment with acids or agents supplying acijds thus splitting ofi of the sulphonic acid group." This treatment is preferably carried out with mineral acids having no oxidizing action, as 'for example sulphuric or hydrochloric acid, or strong organic acids, as for example chloracetic acid or trichloracetic acid. The temperature and duration of the reaction to be employed are to a great extent dependent on the concentration and the degree of dissociation of the acid employed, a decrease in the amount of acid necessitating an increase in the temperature. For example with an acid concentration of. less than 1 per cent of free acid, temperatures of 150 C. or more must be employed.

The treatment with acids may be carried out on the complex chromium compounds of the dyestufis after they have been separated or such separation may be dispensed'with and the said treatment combined with the preparation of the metal compounds. If the complex chromium compound has been produced in acid solution, the

splitting o-fi mayv beefiected by heating for longer periods, advantageously while raising the temperature and if desired while adding further amounts of acid. The complex" chromium dyestufis serving as initial materials may be prepared in any suitable manner, as,,for example by boiling the 5 azo dyestufis with analkaline solution of sodium chromite or by heating the dyestuff, if desired under pressure, with solutions of suitable chromium salts, as for example chromium fluoride or chromium sulphates, or with chromium salts of 10 organic acids, as for example of formic acid, acetic acid or chloracetic acid; mixtures of two or more of such chromium compounds may also be employed. In many cases certain advantages attend the use of the corresponding aminophenol l5 ether sulphonic acidsfor the preparation of the azo dyestufls forming the basis of the complex chromium compounds and their de-alkylating chroming according" to the U. S. Patents Nos. 1,765,680 and 1,978,880. 20 .By splitting off the sulphonicacid group from dyestuffs derived from coupling components containing also sulphonic acid groups, dyestufis which are readily soluble in Water or alkalies may be obtained which are suitable for dyeing wool, 25 silk and leather and also for coloring varnish lacquers. Compared with the initial dyestufis containing chromium, they are in many cases distinguished by considerably better fastness to washing and fulling and a better levelling power 30 and also by a highly improved shadepin artificial 1 lightf In many cases a considerable deepening or change in shade is effected by the treatment withacids." The useof coupling components'free from'sulphonic groups leads to dyestuffs which 35 are almost insoluble in water and sodium carbonatesolution'but somewhat soluble in caustic soda solutions; they are especially valuable as pigment dyestuffs and suitable for coloring varnish laoquers. 40

The following examples Will further illustrate how our invention may be carried out in practice but the invention is not restricted to these exampics. The parts are by weight.

Example 1 45 An azo dyestuff containing chromium is prepared as iollows:-- 24,8 parts of 5 -nitro-2-amino-l-methoxybenzeneflrsulphonic acid are dissolved in 300 parts 50 of water while adding sodum carbonate solution to render the resulting solution neutral. 6.9 parts of sodium nitrite areadded and the solution is allowed to flow into a mixture of parts of hydrochloric acid (specific gravity 1.08) and 55 parts of ice, the resulting :diazo solution being added after the course of an hour to a solution of 35 parts of 2-hydroxynaphthalen'e-3IG-disulphonic acid in 800 parts of water and 30 parts of calcined sodium carbonate. Thedyestufi formed is filtered 01f by suction. A solution of 12 parts of chromium oxide per cent) in 15 parts of sulphuric acid (66 B. strength) is added to the filter cake and the whole diluted to about 1000 parts with water. The whole is then heated in a closed vessel for an hour at C., for an hour at C. and finally for three hours at C. The complex chromium compound formed is separated by the addition of 250 parts of sodium chloride and filtered off by suction. It dyes wool red-violet shades.

The dyestuif containing chromium is then thoroughly stirred with 1000 parts of water, 40 parts of sulphuric acid of 66 B. strength are added and the mixture heated at C. in a closed vessel for three hours. The resulting dyestufi is separated by the addition of 200 parts of sodium chloride. It dyes wool and silk reddish blue shades.

Example 2 The complete chromium dyestuff derived from 5 nitro-Z-amino-1-methoxybenzene-4-sulphonic acid and 1-hydroxynaphthalene-3.8-disulphonic acid in the manner described in Example 1 dyes wool reddish blue shades, but levels badly. By heating for six hours 63.8 parts of the dyestuff with 1000 parts of 4 per cent sulphuric acid at 135 C. a new dyestuff containing chromium is obtained which dyes wool green-blue shades and which levels very well.

Example 3 23.8 parts of 5-chlor-2-amino-l-methoxybenzene-4-sulphonic acid are stirred with 200 parts of water, 200 parts of ice and 10 parts of concentrated hydrochloric acid and diazotized by the addition of a solution of 6.9 parts of sodium nitrite in a little water. The diazo solution is coupled with a solution of 25-parts of 2-hydroxynaphthalene6-sulphonic acid in 1000 parts of water and 30 parts of calcined sodium carbonate. By adding sodium chloride, the dyestuff is separated while stirring, filtered off by suction and a solution of 12 parts of chromium oxide (100 per cent) in 24 parts of formic acid (100 per cent) and 700 parts of water is added. The Whole is heated in a closed vessel for an hour at 125 C., for an hour at 130 C. and finally for two hours at 135 C. The dyestuff is separated by the addition of 250 parts of sodium chloride and filtered off by suction.

The dyestuff containing chromium in the moist state in which it is obtained is made up to about 1000 parts with water and heated in a closed vessel for two hours at C. and for another two hours at C. In this treatment the residue of acid present in the moist chromium complex dyestuff from the chromating process is sumcient to initiate the splitting off of the sulfonic acid group by which a further amount of acid is set free. After stirring for several hours at room temperature, the new dyestuff separates out without the addition of salt. Both the dyestuff which has not been aftertreated and that which has been so treated dye wool bluish Bordeaux red shades but the dyestuif which has been aftertreated yields a dyeing which is considerably more fast to washing.

Example 4 solution of 16 parts of beta-.naphthol in 200 parts of water, 9 parts of caustic soda solution (40 B.) and 30 parts of sodium carbonate. The dyestuff is precipitated with sodium chloride and filtered by suction. A solution of 12 parts of chromium oxide in 15 parts of sulphuric acid of 66 B. strength is added to the filter cake, the mixture is diluted with 800 parts of water and heated for an hour at 120 C., for an hour at 125 C., for two hours at 130 C. and for two hours at 135 C. By cooling the reaction mixture, the dyestufi separates in a well crystallized form. It is filtered oil by suction and is appreciably soluble in water and readily soluble in dilute sodium carbonate solution.

900 parts of water are added to the dyestuif and then 40 parts of sulphuric acid of 66 B. strength; the whole is heated for three hours at 135 C. and then for three hours at 145 C. The dyestuff which has been formed is almost completely precipitated and may be directly filtered off by suction and washed with water. It is almost insoluble in water and dilute sodium carbonate solution, slightly soluble in dilute caustic alkali solutions and readily soluble in organic solvents. It dissolves in varnish lacquers giving fast reddish blue shades of color.

What we claim is:

1. In the process for the production of complex metal compounds of azo dyestuffs corresponding to the general formula wherein X stands for the radicle of a coupling component attached to the azo group in ortho position to a hydroxy group, and wherein R stands for a member of the group consisting of halogen and the nitro group, the step which comprises heating complex metal compounds of azo dyestuffs corresponding to the general formula wherein X stands for the radicle of a coupling component attached to the azo group in ortho position to a hydroxy group, and wherein R stands for a member of the group consisting of halogen andxthe nitro group, vthe ,step which comp-rises heating complex chromium compounds of azo dyestuffs corresponding to the general formula wherein X and R have the aforesaid meaning in the presence of acid reacting substances selected from the group consisting of mineral acids, strong organic acids and substances capable of supplying {such acids.

'3. In the process for the production of complex chromium compounds of azo dyestuffs corresponding to the general formula wherein X stands for the radicle of a coupling component attachedto the azo group in ortho position to a hydroxy group, and wherein R stands for a member of the group consisting of halogen and the nitro group, the step which comprises heating complex chromium compounds of azo dyestuffs corresponding to the general formula wherein X and R have the aforesaid meaning in the presence of acid reacting substances selected from the group consisting of mineral acids strong organic acids and sub-stances capable of supplying such acids at-a temperature above C.

4. In the process for the production of complex metal compounds of .azo dyestuffs corresponding to the general formula wherein X stands for the radicle of a coupling component free from sulphonic gacid groups. attached to the azo group in ,ortho-position to a hydroxy group and wherein R stands for a member of the group consisting of halogen and the nitro group, the step which comprises heating complex metal compounds of azo dyestuffs corresponding tothe general formula wherein X and-R have the aforesaid meaning in the presence of ,acid reacting substances selected from the group consisting of mineral acids, strong organic acids and substances capable of supplyingsuch' acids at a temperature above 100 C.

5. In the processxforjthe production of complex chromium compounds of azo dyestuffs corresponding to the general formula wherein X stand s f 'or the radicle of a coupling component free from vsulphonic acid groups attached to the azo group in ortho-position to a. hydroxy group, and wherein R stands for a member of the group consisting of halogen and the nitro group, the step which comprises heating complex chromium compounds of azo dyestuffs corresponding to the general formula wherein X stands for the radicle of a hydroxy naphthalene attached to the azo group in orthoposition to the hydroxy' group, and wherein R stands for amember-of the group consisting of halogen and the nitro. group, the-step which comprises heating complex metalcompounds of azo dyestuffs corresponding to thegeneralformula "OBI V l N=NX wherein X and R have the aforesaid meaning in the presence of acid reacting substances selected from the group consisting of mineral acids, strong .organicacids and substances. capable of supplying such acidsat atemperature above 100 C.

7. In the process for the production of the complex chromium compound of the azo dyestuff the step which comprises heating the complex chromium compound of the azo dyestufi in the presence of acid reacting substances selected from the group consisting of mineral'acids, strong organic acids and substances capable of supplying such acids at a temperature above C.

8. In the process for the production of the complex chromium compound of the azo dyestuff OH OH the step which comprises heating the complex chromium compound of the azo dyestuff SOaH 303K in the presence of acid reacting substances selected from the group consisting of mineral acids, I

strong organic acids and substances capable of supplying such acids at a temperature above 100 C.

9. In the process for the production of complex metal compounds of azo dyestuffs corresponding to the general formula OsH wherein X and R have the aforesaid meaningvin the presence of acid reacting substances selected from the group consisting of mineral acids, strong organic acids and substances capable of supplying such acids at a temperature above 100 C.

10. In the processfor the production of complex chromium compounds of azo dyestuffs corresponding to the general formula wherein X stands for the'radicle of a hydroxy naphthalene disulfonic acid attached to the azo group in ortho-position to the hydroxy group, and wherein R stands for a member of the group consisting of halogen and the nitro group, the step which comprises heating complex chromium compounds of azodyestufis corresponding to the eneral formula wherein X and B have the aforesaid meaning in the presence of acid reacting substances selected from the group consisting of mineral acids, strong organic acids and substances capable of supplying such acids at a temperature above 100 C.

11. In the process for the production of complex chromium compounds of azo dyestuffs of the general formula wherein X stands for the radicle of a hydroxy naphthalene disulfonic acid attached to the azo group in ortho-position to the hydroxy group, the step which comprises heating complex chromium compounds of azo dyestuffs of the general formula SOBH wherein X has the aforesaid meaning in the presence of acid reacting substances selected from the group consisting of mineral acid, strong organic acids and substances capable of supplying such acids at a temperature above 100 C.

12. In the process for the production of the complex chromium compounds of the azo dyestufi on SOaH V the step which comprises heating the complex chromium compound of the azo dyestuff OH OH SOaH I /N=N@ O2N SOBH SOSH I in the presence of acid reacting substances selected from the group consisting of mineral acids, strong organic acids and substances capable of supplying such acids at a temperature above 100 C.

13. The complex chromium compound of the azo dyestuff OH OH p in??? 01 sonar 1 FRIEDRICH MOLL. FRITZ LANGE. 

